


Euphotic Interlude

by TheDarkSide, WrithingBeneathYou



Category: Naruto
Genre: Gratuitous porn, Illustrated, M/M, Oviposition, Underwater Sex, merman!Tobirama, scales-weird dicks-and everything else that comes with banging a fish man
Language: English
Status: Completed
Published: 2019-06-03
Updated: 2019-08-10
Packaged: 2020-04-07 11:19:20
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 8,407
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19083961
Author URL: https://archiveofourown.org/users/TheDarkSide/pseuds/TheDarkSide, https://archiveofourown.org/users/WrithingBeneathYou/pseuds/WrithingBeneathYou
Summary: For all the lithe grace Tobirama exhibits on the battlefield, Madara thinks he dances even more fluidly in this private skirmish between them.(Warning: NSFW illustration)





	1. Like real people do

**Author's Note:**

> This is a RP collab set in TheDarkSide's phenomenal [Freshwater Kelp](16754563) universe, where-in Tobirama is transformed into a merman after a jutsu mishap. If you haven't yet, go read it! It's amazing! <3

 

 

It starts with gentle touches.

Hesitant, gloved fingers over rough scales. Tobirama wouldn’t call it shy, Madara is too brash a person to be timid about things like this. Nonetheless, it’s teasing. Soft strokes that draw shudders of anticipation down the length of his spine, fins jerking upright to break through the shallow water where they lie curled together. Kisses follow, brushing over the more delicate scales on Tobirama’s neck and dusting up to his lips where they linger.

“Madara.” He doesn’t want to stop. It’s far too tempting to give in to the fingers trailing blooms of heat in their wake down his belly, but he can’t help being cautious with a body like his. He’s never done this before, not when he had legs and certainly not after he gained a tail.

There’s grumbling that he feels against his side, but the kisses don’t stop and wandering hands are next to join the fray.

Madara lightly drags his teeth along Tobirama’s jaw, maps the rise and fall of scales with his tongue. That he’s allowed this close—invited to nestle up against Tobirama’s most vulnerable parts—is a heady feeling. It ignites something warm and protective in his chest, something covetous.

He hums in response to his name, but doesn’t give up chasing the taste of river water down Tobirama’s neck.

The heat of Madara’s tongue makes Tobirama hiss and shudder. His clawed hand grips Madara’s bicep. It’s almost frightening, the urges that warm lips draw out of him.

He’s lost his train of thought, the question of Madara’s willingness brushed away by the heat of his ma- _partner_ pressed up against him. A slow brush of his tail against the pebbled river bed rolls them halfway and he props himself up to stare at dark eyes.

Inky locks wave in the water, drawing his eye. A slow rake of his claws through Madara’s hair, and Tobirama can’t resist brushing a hint of needle teeth along the collar bone exposed to him.

Only half mindful of the line of spines along Tobirama’s back, Madara wraps a leg around his waist and arches up against him unabashedly. The dangerous pinpricks of teeth so near his exposed throat have him rutting, strong and slow against Tobirama’s flank.  

The warring factions of shinobi instincts and lust pull at him just as strongly as his sodden clothing in the current. It’s too late for caution, though. He buries his fingers in Tobirama’s hair and wrenches him back just enough to study the light dusting of blue across his cheeks, the glimmer of nearly translucent teeth.

Then, he’s flowing forward with all the inevitability of the tide—sharing breath and pouring every ounce of pent up need into trying to measure the weight of Tobirama’s tongue against his own.

His groan vibrates through them where they touch, a mangled attempt at Tobirama’s name.

The firm line of Madara's cock has Tobirama’s own pressing insistently against the muscle of his vent. The first drag of movement causes his lids to flutter over his eyes as they cross in pleasure.

Madara's lips on his draws a deep rumble from his chest, animalistic and possessive.

 

Claws hook in indigo robes turned near black by the water, pulling until fabric parts to reveal pale skin. Tobirama is already too far gone to resist. Their lips part, pebbles scraping as the muscular length of his tail drags him down Madara's body.

The smooth stones of the river bed are an exquisite pressure, and Tobirama dips his head to lave his rough tongue across the pale square of chest bared to him. He parts the robe with nudges of his nose to get at the thin skin of Madara's ribs and nips him there.

Madara’s hips jerk at the bright sparks of pain that shoot straight to his loins. He curls forward, stomach clenching, and watches Tobirama’s face slip further beneath the surface of the water.

The beauty of him is staggering, all pale lines and markings like fresh blood. If Madara had any mental faculties to speak of at the moment, he would stop to marvel at the flare of fins where they thrash and catch the sun.

As it stands, all he can do is clutch Tobirama’s shoulders and hiss through clenched teeth at the sky.

When the burn of Tobirama’s bite fades, he collapses back against the bank with a splash. Water laps against his temples, but even the chill of the Naka river can’t soothe the firestorm building in his loins.

“What do you—” Madara asks, voice low and gravelly. “What am I allowed?”

The vibrations of Madara's voice take a moment to filter past the need pressing cotton into Tobirama’s ears. He lifts his head and takes a shuddering inhale as he beholds the man under him.

The heat in Madara's gaze wrecks him.

Tobirama drags the smooth backs of his claws up Madara's thighs. Deft fingers strip away his underwear, before Tobirama curls his tail up. A mindless flick has them rolling again, pushing Madara up astride the base of his lower half. His vent has parted slightly, trails of sticky pre-cum forming a delicate and glistening web where red scales meet pink flesh.

"This is a first for me. I am yours to teach, Madara."

It takes a moment for Madara to claw his way back to lucidity, but when he does, Tobirama’s words hit home like kunai.

“What?” he asks incredulously, voice reaching a pitch he hasn’t managed since puberty. He clenches his legs tightly around Tobirama’s tail and rides out the displeased ripple of muscle.

There was no hesitation when Tobirama first breached the river and slid up the embankment to meet him where he sat. There was no timidity in the scrape of claws along his ankle, nor the slow, inexorable pull on his leg to bring them closer. He had thought…

Madara opens his eyes, unaware he had closed them, and sucks in a sharp breath at the way Tobirama watches him with his jaw slack and pupils fully dilated. He pans down that lovely chest and settles his attention on the glistening evidence of Tobirama’s arousal. It would be so easy to press his erection flat and slide his shaft along those swollen lips, let them part around the entire length of him.

The first to do so, even.

Another groan, this time muffled in the wetness of his glove.

He has no idea what it is he’s envisioning pressing into—much less if it’s even anatomically possible.

“If it’s any consolation, this is my first time with a fish,” he finally blurts out.

Tobirama slides a hand up one of the thighs gripping his tail, draws thin red lines with his claws all the way up to Madara's ass before digging them in just a little.

"I’m not a fish." It's a little mumbled, distracted as he is by the weight of Madara's gaze.

Tobirama lifts his second hand to lay his fingers on the erection bobbing just above his vent. "I _want_ you," he says, more a growl than words, instincts of this body surging up to cloud his head with lust for his mate. The smell of Madara's arousal is thick and heavy in his nose, he wants more.

He drags a slow, light stroke up his lover’s erection and digs the knuckle of his thumb into the muscle alongside his opening as he presses Madara's cock to it. His own hardness, still tucked away tight, twitches and jerks when he dips the head of Madara’s in where he can see his partner gazing so intently.

The squeeze of his sheath around them forces the small ridges on his underside to rub firmly against Madara’s head. A deep groan thunders in his chest when he feels Madara's hardness press against his own, forcing a thick spurt of sticky pre-cum from the tip.

Curiosity and possessiveness surge in him, and he doesn't think twice before swiping a thumb through the clear beads of arousal sticking to the soft scales on the edge of his opening. He glances up into Madara's eyes as he brings it up to taste the mixed essence of himself and his mate.

Madara’s breath hitches and his chakra blooms fire-bright.

The red glow of his Sharingan flickers for a brief second before he can wrest it back down. It takes an almost herculean strength to keep it locked away.

This sudden, unexpected assault on his self-restraint almost unmoors him. There’s an instinctive need to slam forward and in, to hollow out a space for himself where he suspects there is none—to take until they’re both boneless and spent.

“I really don’t think you need any teaching,” he says, sounding punched out and trying to blink away the continued urge to record and covet every memory of Tobirama’s effortless allure.

Ventral scales as soft as lamb’s skin flutter against his thighs, the space between softer still. It’s tight, and shallow, and writhes against his head with alien intent. Coupled with the half-wild look Tobirama is giving him, he wonders if he can come from this alone.

“Fuck,” he whines, more air than sound.  

Loath as he is to shift that sweet pressure away, Madara shudders and catches Tobirama’s wrist, pulling it from his weeping cock and to his mouth instead—a mirror to Tobirama’s own exploration. Blunt teeth sink into the pulse point there, throbbing beneath his lips. Each ache is soothed with a kiss and a swipe of tongue that drags through the combined taste of them on Tobirama’s claws.

Panting softly, Madara smacks his lips and urges Tobirama’s hand down the line of his throat.

Tobirama can feel the mad flutter of chakra behind Madara's eyes and the liquid heat of it as it surges in increments. He melts into it with a gasp as little nips tingle the pads of his fingers only to have the pain-pressure licked away along with sticky tendrils of himself and his mate.

His vision greys when his hand finds the strong pulse of Madara’s throat, breath leaving him at the trust displayed so openly to him. It’s enough to constrict his sheath around the both of them, forcing them out in an exquisite squeeze of muscle.

Tobirama arches, whining high as his member emerges and it takes all of his iron will to halt his orgasm. His cock is throbbing, twitching and jerking between them before seemingly reaching out of its own accord to trap Madara’s between his length and the minute scales around his vent.

“S-sorry, I just-” blood rushes to his face, dusting ears and cheeks pink at the blatant display of how inexperienced, how _inhuman_ he is.

Madara freezes.

“Your dick is prehensile? And you’re _apologizing_?” He takes a bracing inhale, lets it out long and slow—wonders which god’s favor he’s garnered to be given such a gift as the man between his legs.

Easing into the hesitant pressure of Tobirama’s hand, he fights the weight of his wet hair to curl closer. Muscle flexes and coils with Tobirama’s obvious unease but, as in all things, Madara only knows how to advance. He can’t stop. Not when arousal threatens to choke him more surely than the fingers around his throat.

The banked embers of his chakra coils ignite and burst forth into an answering conflagration, one that brings Tobirama’s scales into sharp clarity. A flush on high cheekbones, parted lips, the unexpectedly erotic sight of Tobirama’s member wrapped around his own and pulling, massaging like a thing possessed—this is an image he will take with him always.

He pushes his hips forward, hungry for the feel of it.

“Sage’s balls,” he rasps.

The sight of Madara’s eyes swirling sends a skitter of wild lust down Tobirama’s spine, fingers tightening on the delicate throat they’re wrapped around. Surprise at Madara’s acceptance is chased from his mind by the desire to hold his mate close.

Tobirama drags Madara down to press teeth to his chest, grasping the flesh around his nipple and biting just hard enough to threaten to break the skin. His other hand digs claws into the muscle of Madara’s ass, dragging his rutting mate forward as he flexes the muscles in his member. An arch of his back pulls him in the opposite direction of his mates’ movement, and when he feels the scratch of hair on sensitive flesh, he _squeezes_.

The pad of his index finger trails down to Madara’s entrance, giving it a rough rub.

“ _Mine_.” It’s a deep, hissing rumble around the flesh in his mouth, and Tobirama drags his rough tongue over the nipple pebbled so sweetly for him.

“Ah—” Madara cries out, squirming and torn between pistoning forward into the sweet vice around the base of his cock or slamming back to spit himself on Tobirama’s finger, sharp bits be damned.

“Prove it,” he bites back in challenge. Not for the first time, he wonders at his own lack of self-preservation.

Tobirama rumbles a growl, baring his teeth and pressing them to the soft skin under Madara’s jaw. He’s drooling. It registers distantly, but his mate smells too delicious for him not to want to taste. His mouth opens, hyperextending to fit his teeth just behind the sharp curve of Madara’s jaw. It’s not a threat, just a reminder that he could probably bite clear through to his mate’s spine, and it makes for the perfect distraction.

His hand leaves Madara’s throat, urged by instinct to gather the pre-cum beading thick on the tip of his cock with two fingers. The hand on Madara’s ass spreads him wide, exposing his eagerly fluttering hole to Tobirama’s questing fingers. They smear his essence liberally over muscle, and when he presses his index finger in knuckle-first the tight ring clenches only for a moment before relaxing and allowing him entry.

Madara shouts as the bright ache of too much, too soon makes his vision waver.

Tobirama isn’t his first lover, not by a long shot, but he can’t remember a time when he was ever so unashamedly desperate for it. Some part of him knows he should be more cautious, approach those glass teeth and flashing spines with care. It doesn’t matter, though. He can’t stop picturing them buried in his shoulder while that writhing monstrosity of a dick fills him up and splits him in two.

He bears down and jerks back to take more of Tobirama’s finger, less mindful of the claws than he should be in his eagerness. There’s a warm flow on his neck where Tobirama’s careful hold is jarred into welling up pinpricks of blood.

Madara doesn’t care. This is perfect.  

Between the two of them, he’s has always been the one to act brashly—a man ruled by his emotions. Tobirama was the one to plan, to establish outcome measurements before acting. It’s nice to see that status quo shattered, at least in this.

This is unbridled animal instinct. This is the Senju without reservation, and Madara wants more.

He wants what the rising prickle of static along Tobirama’s fins promises.

“I’m still not convinced,” he manages to choke out, clutching Tobirama’s shoulders like a life-line. “You’ll have to try harder if you want to call me yours.”

The taste of Madara’s blood on Tobirama’s tongue, the hot clench of his passage around his finger, it blurs away the last of his hesitance. To have his mate writhing and desperate for him, goading him for more, drives him mad.

His jaw tenses, gripping and holding as he digs another knuckle against the clenching ring of muscle without pressing in just yet. His cock twitches before curling just a little further down to squeeze behind Madara’s balls. He extends a long finger to rake a hint of claws across the soft skin of his mate’s perineum.

Another quick gathering of pre-cum before he presses the second knuckle in properly, tightening his member around Madara’s and pressing the pad of his finger where the claw has sensitized already delicate skin.

If his mate has breath enough to sass him, then there’s plenty left for begging. “Tell me what you want.” A growl around his tongue as he laps up the blood of their first mating-bite.

Madara swallows hard, throat bobbing as Tobirama’s tongue and voice wash over him.  

It takes a moment for him to parse out the meaning behind the muffled words. When he does, he can’t help the single bark of laughter that escapes him.

“You’re supposed to be the genius here,” he retorts, all daring and challenge. He digs his fingers into Tobirama’s deltoids and sweeps a line up over his shoulders to the transition between delicate ventral scales and dorsal armor.

“Care to postulate?”

With that, he uses the advantage of his position to clench his body tight and all but slam his hips into the loop of muscle still anchored around his throbbing cock. He gasps—head thrown back in reckless abandon—and revels in the slide of Tobirama’s fingers where his hole flutters, too greedy to let them slip out fully.

Tobirama chirrups with surprise, the slide of Madara’s heat through the grip of his cock and the tight clench of his hole around two knuckles dragging an undignified sort of noise from his voice box.

After a moment spent huffing against his mate’s neck, an idea occurs to him.

Releasing his mate’s member and bucking him off onto a coil of his tail is easy. Fingers still buried deep, he shifts the pillowing section of his tail until Madara is flat on his back before relinquishing his bite to trail teeth down the soft belly presented to him. Further down he goes, drawing at least a dozen red lines to mark his path, and presses the flat of his rough tongue to the underside of Madara’s cock. Tobirama lingers a moment, licking up the evidence of his partners’ arousal before moving on. A rub of his nose just under Madara’s balls, a deep inhale before he extends his tongue again to lick at the man’s rim.

Fingers won’t be enough to open him properly, and his instincts urge him to make room for himself. He’s entirely proportionate, after all.

Madara squawks and flails at the unexpected change in position. He shouts even louder at the addition of a prodigious length of tongue slipping between the webbing of Tobirama’s fingers.

Hips quaking, he throws an arm over his forehead to block out the sun and grits his teeth at the absolutely obscene sounds they make.  

“First time, my ass,” he comments, voice rough.

He grabs blindly—ends up with a fistful of hair—and grinds down onto the tongue that feels like a fist. It flexes and drags across nerves that are just this side of too sensitive.

Blood pounds in Madara’s ears, deafening him to his own cries. Water splashes up his thighs with every enthusiastic undulation of Tobirama’s fins. The flats of needle teeth pressed up against his scrotum threaten to unmake him.

It’s too much.

Not enough.

“Tobirama,” he gasps, eyes flaring behind his arm like prayer lanterns.  

A loud exhale blows hot air across skin just shy of pebbling with goosebumps and Tobirama shakes his head slightly just to feel the firm grip on his hair.

“ _Madara_.”

He _wants._

He wants so badly his cock hurts where it wriggles against the pebbles of the riverbed.

Cracking his jaw a little wider and pressing his twisting tongue just shy of that spot that causes Madara’s chakra to spike, he revels in how his mate writhes for him—pulls one fin up to shade Madara’s eyes. He draws his head up for a moment and halts all movement.

“ _Look at me, and tell me what it is you want_.” His instincts won’t let him have Madara until his mate submits properly.

Tobirama lifts his gaze to Madara’s face, he wants to see the moment this powerful man deigns to bend for him.

As contrary as he is by nature, Tobirama’s tone has Madara pausing to reconsider any further goading. He sighs at the loss of tongue where he needs it most and slides his arm up just enough to lock eyes.

“I’ll never get tired,” he says softly, “of the way you say my name.”

It’s not an answer, but true nonetheless.

Madara lets go of Tobirama’s hair to trace the smooth line of his brow and follow it down to the splash of red scales at the outer corner of his eye. His breathing is mostly under control when he pronounces, in no uncertain terms:

“I want you to fuck me, Senju.”

Inhaling shallowly, Tobirama presses a soft kiss to Madara’s belly as he withdraws his fingers. A slow prowl up and continued kisses before he presses his forehead to the thudding space where Madara’s heart lies. He places one last kiss, then brushes his cock where his fingers just were.

He isn’t a man of many words, but now they press against his tongue. He forgoes saying anything for fear of speaking too soon, instead opts to nip softly at the skin of Madara’s pectoral before he slowly presses forward.

His mate’s body parts for him, and Tobirama arches with a howling moan as his head pops in. Madara is _hot_ and _tight_ around him, hole clenching until his cock jerks and shudders with pleasure. A few gulps of air, and he opens his eyes.

Madara watches the pleasure flash across Tobirama’s typically austere face—his mouth works, gaping wide, eyebrows raised towards his hairline.

The first tapered inch fed into him is only a taste of what’s to come. There’s so much more to go and Madara will likely die from that white hot amalgamation of pleasure and pain.

But what a way to go.

He leans forward, dizzy with the rush of it, and presses their foreheads together.

“Easy. Go slow,” he says as calmly as he can, even while his heart races and his stomach clenches with the need for _more_. “We have as long as we need.”

Tobirama chirrups softly at him again, half-lidded eyes drawn up to look into Madara’s Sharingan as he rocks his hips. Instincts beg him to seat himself deep within his mate _now_ , to fill Madara until Tobirama is his only thought, but he takes a stuttering breath and presses in in increments.

The heat of his mate fluttering around him draws him into a blissful trance, and Tobirama drags his tongue and teeth to leave tender licks and nibbles along all the skin he can reach. It takes a few endless moments, but finally he’s almost drawn his hips flush with Madara’s ass. Only the thickest part of his cock remains, closest to the base. He can feel his ridges rubbing against Madara’s walls, the sensation driving shudders up his spine.

Tobirama nearly bottoms out with a groan and it’s all Madara can do not to scream for that final push.

No amount of forewarning could have prepared him for the livewire that Tobirama calls a cock. If the thickness and length alone aren’t enough to send Madara off to the Pure Lands, the way it bucks and writhes against his already raw nerves is. He can feel his erection flag slightly from the overwhelming sensation of being too full.

A string of expletives spills between them, flavoring their shared breath with his desperation.

“Sage. It—it won’t stop moving,” he whines, then buries his face against the crook of Tobirama’s neck and takes a mouthful of flesh between his teeth to stifle his long, low cry.

"It’s because you feel so good. _Madara, mine_."

The teeth against Tobirama’s skin drag up a desperate desire to rut into that heat. The first withdrawal makes his mate shudder, ridges scraping against neigh oversensitive walls. The subsequent thrust drives a whimper from kiss-swollen lips, and Tobirama immediately gentles the strength of his hips.

As much as he wants to pound his mate into the river bed, it would not do to injure him.

A pause, a heavy breath against Tobirama’s shoulder.

“‘Mine’, eh? Wouldn’t have expected the possessiveness,” Madara manages through the haze of pain and passion. Even as he speaks, never once does he stop rolling his hips forward to egg Tobirama on with short, sharp thrusts. Every slick drag feels so good it hurts.

One particularly well-aimed undulation hits his prostate dead on and sets him to keening in a voice he would be embarrassed to claim as his own.

Tobirama’s cock curves up to press at Madara's prostate again, and his next rocking thrust draws out a groan from them both.

His jaws grip his mate’s shoulder, breaking skin to form the second mark of their coupling. He rumbles, rubs himself against his mate to mingle their scents. He wants all and sundry to know exactly whose cock his mate has been taking. Wants to watch his cum dribble out of that clenching hole when they've fucked until his balls run dry.

And, for his part, Madara greedily takes it all.

How this man—this glorious man—can claim to have no experience is beyond him. Maybe it really is just animal instinct. Madara has no clue. He only knows that for all the lithe grace Tobirama exhibits on the battlefield, he dances even more fluidly in this private skirmish between them.

Water begins to lap further up his thighs, frothing where they crash together, and higher still to set his hair floating like an ink spill. He wonders absently if Tobirama realizes they’re floating, then doesn’t think at all when a fin flutters around the curve of his hip to drape over his neglected cock.

Tobirama only realizes they've been drifting as Madara's legs tighten around his tail. After a moment of consideration, he draws a deep breath and submerges them entirely.

When his mate shifts in alarm, passage clenching tight, he presses their lips together and slowly fills his partner’s lungs with air from his own. It drags a dark sort of pride from him— _he's keeping his mate safe, alive_ —and the glee of it makes him grin against Madara's lips. His tail drags up to press against the hardness between his lovers thighs, and the sigh of pleasure fills the water around them with silver bubbles.

Surfacing is a mindless act, and Tobirama skims his claws down his mate’s soft belly to brush the pad of a finger against where they merge. His hips are set at an almost leisurely roll, simply to enjoy their coupling now that the frenetic buzz of his instinctual demands has been mostly silenced.

Madara clings a bit more tightly, still intent on memorizing Tobirama’s lips and swallowing his air. Every light, sweet drag of fin against his cockhead, coupled with the slowed pace, is surely intended to drive him mad.

“You,” he half snarls between kisses, “are an insufferable tease.”

He takes one last taste and pulls away, dragging Tobirama’s bottom lip between his teeth.

Without warning, he pushes against his lover’s hold, hooks the tops of his feet on Tobirama’s tail and eases them apart the next time his hips roll back. It’s agony not being so thoroughly filled, but a change in position will be worth the momentary loss.

If Tobirama insists on such a languorous pace, Madara is at least going to take every inch of cock he can get—press those delicate scales _flush_ against his buttocks.

He grins at the feel of Tobirama’s long, sinuous member squirming against his thigh in rebellion and goes under, using the current to help him turn.

His robes and hair billow like sails around him. Water fills his mouth.

Tobirama’s very being rings like a struck gong. _Where is our mate going_ \- _challenger - find and hold and fill_ \- and he reaches out with chakra.

Madara notes the doleful note in the water, the flare of chakra filled with an emotion he can’t quite parse out. Then, Tobirama’s hands are right there to catch him by the hips and reel him back in. A flash of white in his periphery, a wall of muscle sliding against his buttocks, and he’s being spitted once more on too much, too soon.

His scream comes out as a screen of bubbles. Starbursts of pleasure nearly blind him.

It’s everything he could possibly hope for.

Suddenly, claws pull at his hair and Tobirama’s mouth slots easily over his own, gifting him with another rush of air that he doesn’t need yet, but so desperately wants.

When they breach the surface again, Madara can only arch into the steely arm that encircles his waist and let his head fall back on a strong shoulder.

“You’ll be the death of me,” Madara rasps.

Tobirama is so lost in pleasure the words don't register past the feeling of wholeness.

He bares his teeth, cracks his jaw wide open and bites deep into the bare shoulder presented to him. Madara wails, hole squeezing tight and Tobirama can feel his orgasm gathering just below his hips. His member swells painfully, raising the ridges and squirming as he lifts his tail up between soft thighs and presses his mate into it. One hand grasps a tense hamstring and digs claws in, spreading him wide to make room for them to join completely. Madara's fluttering entrance stretches around the thickest rise at his base, and when he feels it pulse against his vent his tails curls to tie them in a tight ball of shivering muscle.

Sharp, barbed spikes stand to protect them as his hips jerk, rutting up into that heavenly tightness as his cock writhes to find Madara's deepest point. An attempt at Madara's name and a warning of impending climax comes out as a series of clicks and squeaks, mind too overwhelmed to form human syllables.

Madara clamps his teeth tightly against the broken moan that wants to escape.

Tobirama’s girth was at the limit of his body’s ability to take to begin with. This. This is something else entirely—hot and shaped in such a way to catch at his hole on each retreat, mercilessly dragging across his prostate with every rhythmic return of hips.

A strong pulse of precome in the water. They’re both coming undone, he thinks.

He rocks back hard, clenches as firmly as he can, and takes, and takes, and takes.

His reward is a broken warble at his back that burns through him and tightens the coil of passion in his gut, already so close to the breaking point.

He shifts his hips just enough to turn at the waist and reaches back to anchor an arm around Tobirama’s shoulders. Fabric bunches up between his forearm and the sharp scales there, like interlaced kunai.

As amazing as it is to be filled like this—fucked raw and gasping with it—Madara desperately wants to watch Tobirama come apart. He wants to study all of the wondrous ways pleasure contorts such a handsome face. Wants to embed the image in his eidetic memory for those nights he’s alone with his hand.

His eyelids flutter with the effort to stay open. Pistoning thrusts come quicker now.

Bruising claws dig into his waist.  

He strokes down the corded arm trapping him in and finally— _finally_ —wraps his palm around his neglected erection.

The glide of foreskin and the sweet kiss of the Naka are too much.

Head thrown back, he _wails_ his release.

Madara trembles caged in Tobirama’s arms, there's one squeeze, two, and orgasm is pulled from his gut so quickly it _hurts_.

His mate clenching on his cock draws the first spurt of come out of him, thicker and stickier than any human’s, and his roar joins Madara's voice to scare the birds from the trees.

The world flashes white before his eyes, and yet he still manages to catch and hold the glint of Madara's Sharingan. Their gazes meet as his body seizes, tail constricting around them both as release sweeps over them. They hover together in bliss for a few infinite moments, Tobirama’s body jerking with each stream of semen that leaves his now throbbing member.

By the time he comes down from his high they're nestled together in a shallow dip in the rocks, sluggishly flowing water clouded by their essence. They pant together, Tobirama’s brain stuffed with soft cotton as he cradles his mate to his chest. Then his eyes jerk open, the last vestiges of higher thought tensing the muscles of his tail when something _shifts_ inside him.

He pants through the painful spark of pleasure—still hard inside his lover and absent mindedly stroking a hand up Madara's abdomen to calm himself and his mate—and pauses. He lays his hand flat a little above Madara's spent and softening cock and presses softly. The liquid movement thrills his hind brain.

" _My mate_." Escapes before he can stop it. Revels in the whimper it gets him before staring intently into languidly spinning eyes and stroking the slight bulge under his palm.

"So full of me." It rumbles in his chest, purring with dark pride. " _Mine_."

Madara laughs breathlessly and feels the sting of a dozen shallow scratches and bite-marks, painful now that the endorphins are fading.

“Is that so?” he drawls, though the teasing lilt quickly fades into another quiet little gasp.

Water laps placidly around them as he surrenders and lies boneless in Tobirama’s arms.

“I couldn’t tell,” he quips, arching his neck to display the perfect molds of Tobirama’s teeth. From the throbbing, he can only imagine the edges are beginning to swell and discolor. In an hour, not even the Uchiha’s typical high collar will be able to hide the evidence completely.  

Another bemused huff of laughter and his eyes turn dark, chakra receding.

Tobirama brushes his tongue over the marks, nips and nibbles to turn them just a little darker as he scrapes the tips of his claws over the soft swell of Madara’s abdomen. He laughs softly and tests the resistance of it.

He’s still mostly hard, and the thought, the _feeling_ of his cum distending Madara’s belly sends little fizzles of arousal through him. He wants more, but something _else_. There’s movement in his tail again, below and behind his vent, and this time he frowns. Rests his head against his lover’s neck and chuckles quietly to himself. “I wonder if I lay eggs…”

It’s an absent minded murmur as he presses his free hand against that spot on his tail. It feels solid and muscular, and after a brief moment of idle thought he relaxes his tail, uncurling it and shaping it around them so that he and Madara can languish comfortably.

“Wonder if you what?” Madara hums.

“When we- uhm- earlier when I…” He’s not any good at this. Words don’t come easy, but this is likely something that he will have to explain. Fear of losing Madara constricts his throat, and the sentence is strained. “I felt something move, inside me.” He lifts hesitant eyes to meet Madara’s, afraid to find the disgust that such a thought will surely invoke.

Madara snorts unattractively. “Me too.”

Despite his gruff response, he reaches back and squeezes Tobirama’s hip, shifting to press a chaste kiss against the corner of his downturned lips. “What is it you’re trying to say?”

Tobirama squirms, thinks for a moment before twining their fingers together and pressing their hands where he thinks the muscle thinnest. All it takes is bringing the image of Madara’s face in rapture before his mind’s eye, pressing against where he can still feel the liquid give of his semen in his lover. The thoughts rise unbidden, sending a flash of arousal through him— _Madara, fuller than he is now, little round leathery shapes against his palm as Tobirama breeds him_. There’s movement again, the slide of something firm against their palms. He bites his lip and refuses to meet Madara’s eyes.

The distinct shape of it must have made it obvious.

“Oh Sage, you literally meant ‘eggs’. _Fish_ eggs. Of all the—” Madara stops himself, inhales deeply, and changes tracks.

He takes his time palpating and considering the roundness beneath Tobirama’s skin, then nips him on the chin in warning.

“Fine. But they had better come back out. If I have to explain why I have masago stuck up my ass to a medic, I’m going to hunt you down and fillet you.”


	2. Chapter 2

**Summary for the Chapter:**

> A continuation with oviposition for MadaTobi Week 2019  
> Day 7: August 10th – Fantasy and creatures // Something kinky

**Notes for the Chapter:**

> This chapter picks up directly after the first. I would highly recommend reading both in sequence. ^_^

Any shinobi worth their salt is made to withstand pain. Even so, Madara knows he’s going to be feeling the ache of their coupling for days.

He grunts and pushes up onto his knees and elbows in the shallows of the Naka, cock floating flaccid in the water between his legs. This body of his hasn’t been teenaged for quite some time. The burn of too-soon stimulation overwhelms instead of entices, but it doesn’t matter.

He wants this.

Wants the weight of Tobirama as he moves to lie long and heavy against his back.

Wants his special Senju to claim him and be claimed in turn—push him down in the river mud and fill him with come and eggs both, until they dribble out of his mouth like a fountain. It’s a ridiculous image, but one which stokes those familiar embers of desire in his stomach.

After a moment of consideration, he finds words he thinks will appeal to Tobirama’s unique passions and ignite that conflagration in him as well.

“Tobirama,” he says in a voice gruff from screaming, “stop fucking around and breed me.” 

Tobirama ripples, fins flexing wide before settling again. 

Madara looks absolutely stunning like this, covered in his bites and bruises and scratches. His entrance is puffy and swollen, winking enticingly and he can't help but spread him just a little wider. He strokes a finger across twitching muscle and tastes himself. Satisfied with the way their scents mix, he curls his tail in the river bed and nudges it between Madara’s thighs to support the soft skin of his lover’s belly.

He spreads soft thighs a little wider before slotting his hips between them—slides the last article of Madara's clothing off to scrape teeth across the bare skin presented to him. His cock slides easily into where Madara is warm and waiting, and Tobirama takes his time. He presses in a little at a time just to feel his mate clenching and fluttering around him.

Madara sighs beneath him, and Tobirama settles flat across his back, pressing his mate between his belly and the softer scales on the underside of his tail. 

Spilled come clouds the water white with an opalescent sheen and Madara silently mourns its loss from in him.

But, then there’s a gentle hand moving aside his mass of hair and lips pressed against his nape to sooth him. Tobirama’s long fingers slot between his own, delicate webbing stretched taut over his knuckles where they interlace.

It’s tender and intimate without the desperate freneticism of only a few moments ago.

“You know, first time we were in this position I stabbed you with a senbon,” he says because apparently he has no brain to mouth filter to speak of.

Tobirama chuckles, presses a kiss to Madara's neck before sliding forward until his pelvis brushes the muscle of Madara's ass. "Look who's stabbing who now." It's an erotic rumble over Madara's soft whimper, and Tobirama presses his pretty lover down against the corded strength of his tail, curving his member to brush just shy of Madara's prostate. He hisses with pleasure, growing in Madara's ear- "And I plan on doing it over and over until you think of nothing but how good I feel inside you.” He tilts his hips up to embed himself fully, groaning at the sensation of Madara pulsing around him. “Until your legs tremble when you walk."

Madara chokes on a bark of laughter. It’s good. It’s so unbelievably good—the stretch, the lazy undulation inside of him, the feel of being bracketed by strong arms and completely encased within Tobirama’s armor.

He uses chakra-laced strength to push back against the wall of muscle Tobirama calls a tail and tilt his hips up to receive him more fully. Water sloshes against his cheek, dotting his brow.

“You’re awfully cocky for someone who was so worried about his fish parts not a second ago,” he quips, all gentle tease. “If I had known vague threats were what you needed to fuck me properly, I would have palmed a kunai.”

Tobirama rumbles a laugh, pressing back against Madara in turn and pushing the thickest ridge of his cock into his partner. He draws out his thrusts so they're both consumed by the feel of it hooking on Madara's rim with every retreat.

"Maybe next time I'll fight for the right to this." His instincts sing at the thought, _to prove our worth and show our strength_. He nibbles up a bare shoulder and grinds in deep. "It's not like my fish parts haven't been well received." He slides a hand under Madara's thigh, lifting his leg and bending it over his tail so he can get at the slowly hardening length he can feel as warm pressure against his scales. 

Madara easily shifts his weight and moves with Tobirama, grinding against the cool palm that wraps so confidently around his cock. Lips rounded on a whistled exhale, he reaches back blindly with his free hand and grasps at whatever he can find to anchor himself.

His elbow sinks deeper into the river bank and he has to lift his chin to stay above the surface.

“As amazing as that sounds, you’d be completely outclassed,” he quips, panting at the first stroke of steely silk over his cock. “I’d have to let you win.”

A sharp thrust, powerful and admonishing.

“Every—ah—every time.”

Tobirama growls, squeezing the erection in his hand warningly. “Then perhaps next time -ngh- I’ll let you earn the right to have me.”

He licks a stripe up Madara’s neck, presses in as deep  as he can go—nips and bites as pleasure sinks hot claws into his loins and clouds his brain. His thrusts pick up, timed to Madara’s heartbeat. He leaves more bites and kisses over the darkening purple bruises already there. Lifting their twined hands, he curls the end of his tail around their arms and up under Madara’s throat to keep his head above water.  

He presses their cheeks together and meets his mate’s eye.

Madara’s stomach clenches with an emotion he refuses to name. He shivers, faint, but there, and words are suddenly hard to dredge up past the sudden thickness in his throat. 

Twisting, he captures Tobirama’s mouth in a deep, filthy kiss that tastes like tea and feels like deliverance. He’s mindful of the way Tobirama holds his bottom teeth low so as not to cut, but restraint isn’t what he wants now.

An asynchronous jerk of his hips makes claw tips catch gently against the prominent vein of his shaft. The palm around his cockhead squeezes and the thickness buried in him lashes out, mercilessly slamming into his prostate and whiting out his vision.

His aborted cry is swallowed with more passion than skill—the honesty in Tobirama’s occasional stumble more enticing than anything ever could be.

Madara knows he’s already lost this and every battle to come.

Willingly.

Willfully.

Tobirama jerks, biting softly on Madara’s lips and groaning. He presses Madara down, holds him tight and carefully draws the tip of a claw up the shaft in his hand—along that thick, sensitive vein. It sets his head spinning, how trusting Madara is of him. He sweeps a rough tongue over the rising pinpricks of blood on Madara’s lips before bullying deep and squirming inside his lover. The squeeze around his cock and the drag against the ridges punches a rough noise out of him.

His hips rut mindlessly of their own accord, dragging soft noises of pleasure out of Madara. His head is fuzzy and orgasm is tightening his belly. “Madara, mine, always.” It’s a breathless whisper, he’s not sure it’s properly audible, doesn’t care past the sparks of pleasure flashing behind fluttering eyelids.

“I know,” Madara murmurs into wet skin. Capitulation has never been so easy. “I have been for a while, you stupid Senju.”

The blunt admission steals Tobirama’s breath.

“Madara, I -ah!” The thought of it sets his insides shuddering and he can feel the tightening of orgasm in his belly, the shifting of eggs below his hips. Speech becomes difficult as his muscles start to tense, his member twitching and jerking and already beginning to swell inside his mate. “I’m- ngh- _breed you, mine_.”

The inhuman keen building in Tobirama’s chest resonates.

“Sage’s balls,” Madara hisses. Curling forward, he presses his throat more fully against the mass of fin membrane and spines as he releases Tobirama’s hip. It takes a bit of wriggling, but he manages to reach down between the confusing tangle of limbs and feel for the slit pressed up tightly behind his scrotum. It’s oily and slick, even in the water.

Gritting his teeth to stave off his own impending orgasm, Madara traces the seam where they connect and searches for what Tobirama had pointed out before.

There.

Slight, round protrusions slip from under his fingers with each tentative press against scales. He doesn’t know if this is okay, if what he’s doing is helping or hindering, but he wants it. He needs it so badly.

“Tobi—Tobirama. Fuck.”

Uncoordinated fingers manage to trap an egg and ease it closer to where Tobirama’s cock summarily ruins him for all others.

“Now!”

The pressure builds behind Tobirama’s sheath and it _hurts_ so good. One last brutal thrust before his mate grips him tight and the thick ridge at his base catches, hooking him and Madara together. His cock pulses, shudders almost, when he feels fingers against the tight bundle of eggs inside him. His breath hitches at that pressure, as little palpitations brush more eggs against Madara’s fingers.

He arches back, hips grinding and cock squirming as the first egg presses at his base. Little bursts of fluid leak from his tip, ready to ease the way for the precious leathery globes pressing against the inside of his member. He’s fully engorged now, almost the size of their clasped hands inside his mate. A final shudder sets him keening, and soft eggs begin to slide down his cock, tearing a screaming orgasm from him. His vision grays at the constant pressure against his prostate, member tensing rhythmically inside Madara as the first egg leaves him.

The sheer girth inside of him keeps Madara from finding release fully along with Tobirama. Instead it ramps up in dry spurts, one surge after the other, building towards something that promises to be explosive but can’t quite make it there. Fluttering fin fills his mouth and Madara clamps down on one of the spines with his teeth, roaring into it as he ruts desperately.

There’s even more pressure. Some vague thought—eggs—breaks through the blaring static between his ears. It’s all he can do not to sob with the realization.

Then, something gives, he’s not sure what, and his body clamps down and blinds him with release.

Chakra tears at the water around them in a single sustained burst—fire-hot and explosive.  

Tobirama gasps as chakra stings. The tight grip on his cock makes him hunch over as he’s dragged along with the throes of his mate’s climax. It tears soft little “ah”s out of him. The eggs are a steady pulse now, orgasm a slower but constant rush as his own chakra escapes its coils and meets Madara’s with a hiss of steam.

Tobirama’s head is empty for a few long moments of bliss. When he comes back to himself, the rush of eggs has slowed to just a few at a time. He shudders from the sudden oversensitivity, every brush against his prostate making his cock twitch. It takes a monumental effort to lift his head and peel his eyes open. He turns to lie on his side—bringing Madara along with him—to catch their breath in the hot, shallow water.

This is what dying feels like, Madara thinks languidly. Tobirama is a shinigami and the Pure Lands are a stretch of river bank straddled by two warring clans.

Feeling returns in increments. As it does, he thinks that some Iryō Ninjutsu may be in order. Sharp pains shoot through his shoulders and hips when he shifts. Walking is something he really doesn’t want to consider right now and there’s a sloshing in him that has nothing to do with the water.

Even so, he regrets nothing.

“If you want me to stay yours, you’re going to have to refrain from killing me every time we fuck,” he grunts.

“I never thought you’d be the one to ask to be gentle,” Tobirama croons, voice deep and rough with satiation. He runs a hand down Madara’s belly, fingers flickering green with concern for his mate. The movement in him draws a worried whine, and he props himself up for a better look. Madara’s once flat abdomen is distended, large enough to cause him pain, likely. The healing jutsu is for cuts and scrapes, and makes easy works of any tears. Madara’s face is flushed and ruddy, and his eyes tightly shut. “Madara?”

At the sound of his name, Madara turns and blinks up blearily. He snorts at the concern he finds in Tobirama’s expression.

“Relax, Senju. I’m fine.”  A squeeze of their still interlaced fingers belies the affection beneath his surly tone. “More than fine.”

“Do you want to get these out?” Tentative fingers stroke down Madara’s belly, and Tobirama holds him close. His hips rock back, cock beginning to slide back into his vent.

Madara hums and settles back against Tobirama’s chest.

“Not yet,” he admits, in no way eager to return to the rigors of clan and politics. “Let’s just lie here a while.” He pulls Tobirama’s foremost fin over his hip like a blanket and takes comfort in the answering thrum that means his response was well received.

Sunlight warms his face as his heart settles in the shape of Tobirama’s name.

 

**Author's Note:**

> Art by [WrithingBeneathYou](https://writhingbeneathyou.tumblr.com).


End file.
